22:18 furnace. The periodic outpouring of divine judgment on Israel was designed to purge her of sin and to produce a pure people (6:8 note). Israel’s experience in Egypt was likened to time in a furnace (Deut. 4:20; 1 Kin. 8:51; Jer. 11:4), and the Exile would be a refiner’s furnace for Israel. Refining is a common image in the Bible (Ps. 66:10; 119:119; Prov. 17:3; 25:4; Is. 1:25; 48:10; Jer. 9:7; Zech. 13:9; Mal. 3:2, 3; 1 Cor. 3:12–15; 1 Pet. 1:7).